Noisy work environments do not always lend themselves to easy communication between co-workers. For example, logging and tree service workers are constantly working amid the noise of power saws, heavy equipment, etc. Exposure to loud noise over time also tends to reduce the hearing ability of such workers. Protective devices such as earplugs also serve to reduce the ability of workers in such environments to hear warnings and communications from co-workers. Such environments pose immediate dangers to workers, who must often rely on their fellow workers to warn them of danger. Effective and reliable communication among co-workers in such environments is essential.